Spatially resolved spectroscopy across stellar surfaces. Paper IV: F, G, and K-stars: Synthetic 3D spectra at hyper-high resolution and paper V: Observational prospects: toward Earth-like exoplanet detection

Vol. 648
8. Stellar astmospheres

Spatially resolved spectroscopy across stellar surfaces. Paper IV: F, G, and K-stars: Synthetic 3D spectra at hyper-high resolution and paper V: Observational prospects: toward Earth-like exoplanet detection

Transits of exoplanets across their host stars have brought us a great wealth of exoplanetary information, ranging from the chemical compositions of planetary atmospheres to the statistical properties of exoplanetary systems. These transits also represent powerful probes of the atmosphere of the host star, probably less intuitively, since the difference between occulted and unocculted observations isolates the light from a tiny fraction of the star along the path of the transit. This provides a linear resolution on the surface of those stars, which is set by the diameter of the planet and is otherwise unmatched except on our Sun. In a pair of papers, Dravins, Ludwig, and Freytag use 3D model atmospheres to synthesize the signal from such high spectral resolution differential spectroscopy and find that its observation at a very high signal-to-noise ratio is able to probe fine details of the atmospheric structure of the star.